I used to be a hikikomori for about five years. After years of suffering from anxiety problems and trying my best to break my habit, I finally found the answer. I'm sure this answer will work for most hikikomori, if they're willing to go through with it. Don't stop reading just because this sounds lame.

Volunteering. When you volunteer, you can go as often as you want and people will treat you like you're the best person in the world for doing it, especially if you're a young person. Being around those old Christian ladies is a really refreshing. It's like having 20 Grandmas. Those people rely on you, and it gives you a sense of purpose, even if it's just helping them to lift a crate of food that would otherwise hurt their backs. Every town has volunteer work that needs done, even if it's just going to an old man's house every week to help him rake up some leaves.

Seriously, try it out. When I was recovering from my hiki-state, I first began volunteering at a food bank about once a month, and soon got up to three times a week. Since then, my self-confidence has never been higher, I feel great and I'm in shape (from lifting crates of food and moving furniture in their thrift store), and I've even started a relationship. Volunteering is much simpler than having a job, as you're not required or expected to go in on a schedule. Try it out. If it doesn't work out for you, come back and we'll give you some more ideas, but don't brush it off just because you're feeling lazy or don't think it will work.

Best of luck.